pwsh -Command is removing quotation marks

by

Unfortunately, PowerShell’s handling of passing arguments with embedded " chars. to external programs – which includes PowerShell’s own CLI (pwsh) – is fundamentally broken (and always has been), up to at least PowerShell 7.2.2:

You need to manually \-escape " instances embedded in your arguments in order for them to be correctly passed through to external programs (which happens to be PowerShell in this case as well):

# Note: The embedded '' sequences are the normal and expected
#       way to escape ' chars. inside a PowerShell '...' string.
#       What is *unexpected* is the need to escape " as \"
#       even though " can normally be used *as-is* inside a '...' string.
pwsh -Command ' ''{\"drop_attr\": \"name\"}'' '

Note that I’m assuming your intent is to pass a JSON string, hence the inner '' ... '' quoting (escaped single quotes), which ensures that pwsh ultimately sees a single-quoted string ('...'). (No need for an explicit output command; PowerShell implicitly prints command and expression output).

Another way to demonstrate this on Windows is via the standard choice.exe utility, repurposed to simply print its /m (message) argument (followed by verbatim [Y,N]?Y):

# This *should* preserve the ", but doesn't as of v7.2
PS> choice /d Y /t 0 /m '{"drop_attr": "name"}'
{drop_attr: name} [Y,N]?Y      # !! " were REMOVED

# Only the extra \-escaping preserves the "
PS> choice /d Y /t 0 /m '{\"drop_attr\": \"name\"}'
{"drop_attr": "name"} [Y,N]?Y  # OK

Note that from inside PowerShell, you can avoid the need for \-escaping, if you call pwsh with a script block ({ ... }) – but that only works when calling PowerShell itself, not other external programs:

# NOTE: Works from PowerShell only.
pwsh -Command { '{"drop_attr": "name"}' }

Background info on PowerShell’s broken handling of arguments with embedded " in external-program calls, as of PowerShell 7.2.1:

  • This GitHub docs issue contains background information.

  • GitHub issue #1995 discusses the problem and the details of the broken behavior as well as manual workarounds are summarized in this comment; the state of the discussion as of PowerShell [Core] 7 seems to be:

    • A fix is being considered as an experimental feature, which may become an official feature, in v7.3 at the earliest. Whether it will become a regular feature – i.e whether the default behavior will be fixed or whether the fix will require opt-in or even if the feature will become official at all – remains to be seen.

      • Fixing the default behavior would substantially break backward compatibility; as of this writing, this has never been allowed, but a discussion as to whether to allow breaking changes in the future and how to manage them has begun: see GitHub issue #13129.

    • See GitHub PR #14692 for the relevant experimental feature, which, however, as of this writing is missing vital accommodations for batch files and msiexec-style executables on Windows – see GitHub issue #15143.

  • In the meantime, you can use the PSv3+ ie helper function from the Native module (in PSv5+, install with Install-Module Native from the PowerShell Gallery), which internally compensates for all broken behavior and allows passing arguments as expected; e.g.,
    ie pwsh -Command ' ''{"drop_attr": "name"}'' ' would then work properly.

More Related Contents:

  1. this code my teacher gave it to us as homework and it does not work with me idk why
  2. How can you use an object’s property in a double-quoted string?
  3. Powershell function call changing passed string into int
  4. Different behaviour and output when piping in CMD and PowerShell
  5. PowerShell’s parsing modes: argument (command) mode vs. expression mode
  6. How do I capture the output into a variable from an external process in PowerShell?
  7. How to get an object’s property’s value by property name?
  8. Delete files older than 15 days using PowerShell
  9. Output (“echo”) a variable to a text file
  10. Powershell equivalent of bash ampersand (&) for forking/running background processes
  11. INI file parsing in PowerShell
  12. Parameter interpretation when running jobs
  13. Powershell: Uninstall application by UpgradeCode
  14. How to properly -filter multiple strings in a PowerShell copy script
  15. Methods to hex edit binary files via Powershell
  16. How remove accents in PowerShell?
  17. Unable to convert a string to an integer variable from DateTaken attribute on a JPG file
  18. How to Grant permission to user on Certificate private key using powershell?
  19. Using Invoke-Command -ScriptBlock on a function with arguments
  20. How to use PowerShell copy-item and keep structure
  21. Powershell – Reboot and Continue Script
  22. How can I execute an external program with parameters in PowerShell?
  23. Rename file on FTP with PowerShell
  24. Does PowerShell support HashTable Serialization?
  25. Check if a file exists or not in Windows PowerShell?
  26. Variable scoping in PowerShell
  27. Read a Csv file with powershell and capture corresponding data
  28. List hidden sub-directories and sizes
  29. PS Script is exporting an empty CSVs
  30. Drag and Drop to a Powershell script

Leave a Comment